[PATCH net 5/6] mptcp: drop legacy code around RX EOF

From: Matthieu Baerts
Date: Tue Jun 20 2023 - 12:25:26 EST


From: Paolo Abeni <pabeni@xxxxxxxxxx>

Thanks to the previous patch -- "mptcp: consolidate fallback and non
fallback state machine" -- we can finally drop the "temporary hack"
used to detect rx eof.

Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Reviewed-by: Mat Martineau <martineau@xxxxxxxxxx>
Signed-off-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
---
net/mptcp/protocol.c | 49 -------------------------------------------------
net/mptcp/protocol.h | 5 +----
2 files changed, 1 insertion(+), 53 deletions(-)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 27d206f7af62..a66ec341485e 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -894,49 +894,6 @@ bool mptcp_schedule_work(struct sock *sk)
return false;
}

-void mptcp_subflow_eof(struct sock *sk)
-{
- if (!test_and_set_bit(MPTCP_WORK_EOF, &mptcp_sk(sk)->flags))
- mptcp_schedule_work(sk);
-}
-
-static void mptcp_check_for_eof(struct mptcp_sock *msk)
-{
- struct mptcp_subflow_context *subflow;
- struct sock *sk = (struct sock *)msk;
- int receivers = 0;
-
- mptcp_for_each_subflow(msk, subflow)
- receivers += !subflow->rx_eof;
- if (receivers)
- return;
-
- if (!(sk->sk_shutdown & RCV_SHUTDOWN)) {
- /* hopefully temporary hack: propagate shutdown status
- * to msk, when all subflows agree on it
- */
- WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | RCV_SHUTDOWN);
-
- smp_mb__before_atomic(); /* SHUTDOWN must be visible first */
- sk->sk_data_ready(sk);
- }
-
- switch (sk->sk_state) {
- case TCP_ESTABLISHED:
- inet_sk_state_store(sk, TCP_CLOSE_WAIT);
- break;
- case TCP_FIN_WAIT1:
- inet_sk_state_store(sk, TCP_CLOSING);
- break;
- case TCP_FIN_WAIT2:
- inet_sk_state_store(sk, TCP_CLOSE);
- break;
- default:
- return;
- }
- mptcp_close_wake_up(sk);
-}
-
static struct sock *mptcp_subflow_recv_lookup(const struct mptcp_sock *msk)
{
struct mptcp_subflow_context *subflow;
@@ -2161,9 +2118,6 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
break;
}

- if (test_and_clear_bit(MPTCP_WORK_EOF, &msk->flags))
- mptcp_check_for_eof(msk);
-
if (sk->sk_shutdown & RCV_SHUTDOWN) {
/* race breaker: the shutdown could be after the
* previous receive queue check
@@ -2681,9 +2635,6 @@ static void mptcp_worker(struct work_struct *work)

mptcp_pm_nl_work(msk);

- if (test_and_clear_bit(MPTCP_WORK_EOF, &msk->flags))
- mptcp_check_for_eof(msk);
-
mptcp_check_send_data_fin(sk);
mptcp_check_data_fin_ack(sk);
mptcp_check_data_fin(sk);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 70c957bc56a8..d3783a7056e1 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -113,7 +113,6 @@
/* MPTCP socket atomic flags */
#define MPTCP_NOSPACE 1
#define MPTCP_WORK_RTX 2
-#define MPTCP_WORK_EOF 3
#define MPTCP_FALLBACK_DONE 4
#define MPTCP_WORK_CLOSE_SUBFLOW 5

@@ -476,14 +475,13 @@ struct mptcp_subflow_context {
send_mp_fail : 1,
send_fastclose : 1,
send_infinite_map : 1,
- rx_eof : 1,
remote_key_valid : 1, /* received the peer key from */
disposable : 1, /* ctx can be free at ulp release time */
stale : 1, /* unable to snd/rcv data, do not use for xmit */
local_id_valid : 1, /* local_id is correctly initialized */
valid_csum_seen : 1, /* at least one csum validated */
is_mptfo : 1, /* subflow is doing TFO */
- __unused : 8;
+ __unused : 9;
enum mptcp_data_avail data_avail;
u32 remote_nonce;
u64 thmac;
@@ -720,7 +718,6 @@ static inline u64 mptcp_expand_seq(u64 old_seq, u64 cur_seq, bool use_64bit)
void __mptcp_check_push(struct sock *sk, struct sock *ssk);
void __mptcp_data_acked(struct sock *sk);
void __mptcp_error_report(struct sock *sk);
-void mptcp_subflow_eof(struct sock *sk);
bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk)
{

--
2.40.1